5. A small remote-controlled race car has a mass of 150 grams. If the car starting from rest can reach its maximum velocity of 24 m/s in 4 seconds. What is the force of the race car's motor? (5
pts)

0.9 N.

Explanation:

Mass (m) of car = 150 g

Initial velocity (u) = 0 m/s

Final velocity (v) = 24 m/s

Time (t) = 4 s

Next, we shall determine the acceleration of the car. This can be obtained as follow:

Initial velocity (u) = 0 m/s

Final velocity (v) = 24 m/s

Time (t) = 4 s

Acceleration (a) =?

v = u + at

24 = 0 + (a × 4)

24 = 0 + 4a

24 = 4a

Divide both side by 4

a = 24 /4

a = 6 m/s²

Thus, the acceleration of the car is 6 m/s²

Next, we shall convert 150 g to Kg. This can be obtained as follow:

1000 g = 1 kg

Therefore,

150 g = 150 g × 1 Kg / 1000 g

150 g = 0.15 Kg

Thus, 150 g is equivalent to 0.15 Kg

Finally, we shall determine the force of the car as follow:

Mass (m) of car = 0.15 Kg

Acceleration (a) of car = 6 m/s²

Force (F) of car =?

F = m × a

F = 0.15 × 6

F = 0.9 N

Therefore, the force of the car is 0.9 N.

powerful computers now, not then

the minimum constant speed at which she can catch the train is 2.7 m/s

given:

acceleration = 0.6

time = 4.5 s

to find:

velocity = ?

formula used:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

solution:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

v = 0 + (0.6 × 4.5)

v = 2.7 m/s

the minimum constant speed at which she can catch the train is 2.7 m/s