Answer:
14.6 m/s
Explanation:
Momentum is conserved in the north:
m₁ u₁ + m₂ u₂ = m₁ v₁ + m₂ v₂
After the collision, they stick together, so v₁ = v₂ = v.
m₁ u₁ + m₂ u₂ = (m₁ + m₂) v₂
(980 kg) (0 m/s) + (1500 kg) u = (980 kg + 1500 kg) vᵧ
1500 u = 2480 vᵧ
Momentum is conserved in the east:
m₁ u₁ + m₂ u₂ = (m₁ + m₂) v₂
(980 kg) (22.3 m/s) + (1500 kg) (0 m/s) = (980 kg + 1500 kg) vₓ
21854 = 2480 vₓ
vₓ = 8.81 m/s
The angle of v is 45.0°, so vᵧ = vₓ.
1500 u = 2480 (8.81 m/s)
u = 14.6 m/s
Answer:
If she is walking 30 feet every 10 seconds, that means she is walking 180 feet per minute. Multiply that by the 60 minutes in an hour, means she walks (180x60)= 10,800 feet an hour.
She walks 3 feet a second.
She walks 180 feet a minute.
She walks 10,800 feet an hour.
Explanation:
I assume the 100 N force is a pulling force directed up the incline.
The net forces on the block acting parallel and perpendicular to the incline are
∑ F[para] = 100 N - F[friction] = 0
∑ F[perp] = F[normal] - mg cos(30°) = 0
The friction in this case is the maximum static friction - the block is held at rest by static friction, and a minimum 100 N force is required to get the block to start sliding up the incline.
Then
F[friction] = 100 N
F[normal] = mg cos(30°) = (10 kg) (9.8 m/s²) cos(30°) ≈ 84.9 N
If µ is the coefficient of static friction, then
F[friction] = µ F[normal]
⇒ µ = (100 N) / (84.9 N) ≈ 1.2