Work formula:
F = 50N, d = 1.0 m
When you lift something straight up, the angle of the force is 90º
cos(90º) is 0, so there's no work done when you lift the microwave off the ground
F = 50N, d = 1.0 m
When you push the microwave, the angle is 0º and cos(0º) is 1. So there is work done here:
total work = 50 joules
Answer:
Explanation:
As we know,
=》Force = Mass × Acceleration
=》45 N = 0.75 × Acceleration
=》Acceleration = 45 ÷ 0.75
=》Acceleration = 60
hence, the Acceleration of the ball would be. 60 meters per second square
Answer:
ΔK = -6 10⁴ J
Explanation:
This is a crash problem, let's start by defining a system formed by the two trucks, so that the forces during the crash have been internal and the moment is preserved
initial instant. Before the crash
p₀ = m v₁ + M 0
final instant. Right after the crash
p_f = (m + M) v
p₀ = p_f
mv₁ = (m + M) v
v =
we substitute
v = 3
v = 1.0 m / s
having the initial and final velocities, let's find the kinetic energy
K₀ = ½ m v₁² + 0
K₀ = ½ 20 10³ 3²
K₀ = 9 10⁴ J
K_f = ½ (m + M) v²
K_f = ½ (20 +40) 10³ 1²
K_f = 3 10⁴ J
the change in energy is
ΔK = K_f - K₀
ΔK = (3 - 9) 10⁴
ΔK = -6 10⁴ J
The negative sign indicates that the energy is ranked in another type of energy