science

Grade-9

Easy

Question

# A car moving at a velocity of 5 m/s accelerates to 25 m/s while covering a distance of 1.8 km. The time it takes to cover that distance is ___ seconds.

Hint:

### 120 s

## The correct answer is: 120

### Given that,

The initial velocity, u = 5 m/s

The final velocity, v = 25 m/s

The distance covered, s = 1.8 km = 1800 m

On using the third equation of motion we get,

v^{2} = u^{2} + 2as

Or, (25)^{2} = (5)^{2} + 2 x a x 1800

Or, 625 = 25 + 3600 a

Or, 3600 a = 625 – 25

Or, 3600 a = 600

Or, a = 600/ 3600 = 1/6 m/s^{2}

Therefore, the acceleration of the car is 1/6 m/s^{2}.

On using the first equation of motion we get,

v = u + at

Or, 25 = 5 + (1/6) x t

Or, t/6 = 20

Or, t = 20 x 6

Or, t = 120 s

Therefore, the time taken by the car is 120 s.

### Related Questions to study

science

### A ball is dropped from the top of a building of height 80 m. Considering the acceleration due to gravity of the Earth to be 10 m/s^{2}, the time it takes to hit the ground is ____s

### A ball is dropped from the top of a building of height 80 m. Considering the acceleration due to gravity of the Earth to be 10 m/s^{2}, the time it takes to hit the ground is ____s

scienceGrade-9

science

### The displacement of the body whose v-t graph is given below is ____ m.

### The displacement of the body whose v-t graph is given below is ____ m.

scienceGrade-9

science

### The x-intercept and the y-intercept of a v-t graph represent ___ and ___ respectively.

### The x-intercept and the y-intercept of a v-t graph represent ___ and ___ respectively.

scienceGrade-9

science

### In a running race between 4 people, the 1^{st} person did not start running as soon as the whistle was blown. He started running after a few seconds. The x-intercept of the v-t graph of the 1^{st} person is ___.

### In a running race between 4 people, the 1^{st} person did not start running as soon as the whistle was blown. He started running after a few seconds. The x-intercept of the v-t graph of the 1^{st} person is ___.

scienceGrade-9

science

### A stone is thrown upwards. It moves upwards for some time and then starts falling down. The velocity that the stone has just before touching the ground is ___.

### A stone is thrown upwards. It moves upwards for some time and then starts falling down. The velocity that the stone has just before touching the ground is ___.

scienceGrade-9

science

### An object is moving at some velocity increases its speed later. The y-intercept of its v-t graph is ___.

### An object is moving at some velocity increases its speed later. The y-intercept of its v-t graph is ___.

scienceGrade-9

science

### The acceleration of the body whose v-t graph is given below is ____ m/s^{2}.

### The acceleration of the body whose v-t graph is given below is ____ m/s^{2}.

scienceGrade-9

science

### Which of the following quantities cannot be calculated by directly using the second equation of motion?

### Which of the following quantities cannot be calculated by directly using the second equation of motion?

scienceGrade-9

science

### The area under the v-t graph represents the ____ of the moving body.

### The area under the v-t graph represents the ____ of the moving body.

scienceGrade-9

science

### In a mathematical problem, Samuel was provided with the values of s, u, and a and the value of t was asked to be calculated. Samuel substituted those values into the second equation of motion and got a quadratic equation in t as a result. He thought of plotting a graph taking t in the x-axis. How will the graph look like?

### In a mathematical problem, Samuel was provided with the values of s, u, and a and the value of t was asked to be calculated. Samuel substituted those values into the second equation of motion and got a quadratic equation in t as a result. He thought of plotting a graph taking t in the x-axis. How will the graph look like?

scienceGrade-9

science

### A ball is thrown upwards, the velocity of the ball when it reaches the maximum height is ___.

### A ball is thrown upwards, the velocity of the ball when it reaches the maximum height is ___.

scienceGrade-9

science

### In a running race between 4 people, the 2^{nd} person started running few seconds earlier than the rest. The x-intercept of the v-t graph of the 2^{nd} person is ___.

### In a running race between 4 people, the 2^{nd} person started running few seconds earlier than the rest. The x-intercept of the v-t graph of the 2^{nd} person is ___.

scienceGrade-9

science

### An object starts from rest. The y-intercept of its v-t graph is ___

### An object starts from rest. The y-intercept of its v-t graph is ___

scienceGrade-9

science

### The displacement of the body whose v-t graph is given below is ____ m.

### The displacement of the body whose v-t graph is given below is ____ m.

scienceGrade-9

science

### A ball is dropped from the top of a building of height 80 m. Considering the acceleration due to gravity of the Earth to be 10 m/s^{2}, the velocity of the ball right before it touches the ground is ____ m/s.

### A ball is dropped from the top of a building of height 80 m. Considering the acceleration due to gravity of the Earth to be 10 m/s^{2}, the velocity of the ball right before it touches the ground is ____ m/s.

scienceGrade-9