A body of mass 10kg and initially at rest us subjected to a force of 20N through a distance of 10m. calculate the change in kinetic energy of the body?
To calculate the change in kinetic energy, we need to use the formula:
ΔKE = KE_final - KE_initial
Given:
Mass (m) = 10 kg
Force (F) = 20 N
Distance (d) = 10 m
First, we need to calculate the work done on the body using the formula:
Work (W) = Force × Distance
W = F × d
W = 20 N × 10 m
W = 200 N·m or 200 J (Joules)
The work done on the body is equal to the change in kinetic energy. So, ΔKE = W = 200 J.
Therefore, the change in kinetic energy of the body is 200 Joules.
A body of mass 5kg moving with a speed of 30m/s-1 is suddenly hit by another body moving in the same direction.thereby changing the speed of the former body to 60m/s-2.what is the impulse received by the first body?
To calculate the impulse received by the first body, we can use the impulse-momentum principle, which states that the impulse experienced by an object is equal to the change in its momentum.
Given:
Mass of the first body (m1) = 5 kg
Initial velocity of the first body (u1) = 30 m/s
Final velocity of the first body (v1) = 60 m/s
To find the impulse (J), we can use the formula:
J = m1 * (v1 - u1)
J = 5 kg * (60 m/s - 30 m/s)
J = 5 kg * 30 m/s
J = 150 kg·m/s
Therefore, the impulse received by the first body is 150 kg·m/s.
To calculate the change in kinetic energy of the body, we need to use the formula:
Change in kinetic energy (ΔKE) = Work done (W)
The work done on an object can be calculated using the formula:
Work done (W) = Force (F) x Distance (d) x Cosine of the angle between the force and displacement (θ)
In this case, the force and distance are given:
Force (F) = 20N
Distance (d) = 10m
Since the body is initially at rest, there is no initial kinetic energy, so the change in kinetic energy will be equal to the work done.
Now, we can calculate the change in kinetic energy:
ΔKE = W = F x d x cos(θ)
In this case, the angle between the force and the displacement is not given, so we will assume it to be 0 degrees (cos(0) = 1).
ΔKE = 20N x 10m x cos(0)
= 20N x 10m x 1
= 200 Joules
Therefore, the change in kinetic energy of the body is 200 Joules.