Answer:
Parachute exerts a force of 619.2 N upward
The net force is 86.4 N acting downward
Explanation:
As the gravitational acceleration g = 9.8 m/s2, the parachute help reduces the net acceleration to 1.2m/s. So it must exerted an upward acceleration on the skydiver of
9.8 - 1.2 = 8.6 m/s2
Since the skydiver mass is 72 kg, we can use Newton's 2nd law to calculate the force that causes this acceleration of 8.6
F = ma = 8.6*72 = 619.2 N acting upward
The net force is also the product of net acceleration and mass
= 1.2 * 72 = 86.4 N acting downward
Answer:
F = 800 [N]
Explanation:
To be able to calculate this problem we must use the principle of momentum before and after the impact of the hammer.
We must summarize that after the impact the hammer does not move, therefore its speed is zero. In this way, we can propose the following equation.
ΣPbefore = ΣPafter

where:
m₁ = mass of the hammer = 0.15 [m/s]
v₁ = velocity of the hammer = 8 [m/s]
F = force [N] (units of Newtons)
t = time = 0.0015 [s]
v₂ = velocity of the hammer after the impact = 0
![(0.15*8)-(F*0.0015) = (0.15*0)\\F*0.0015 = 0.15*8\\F = 1.2/(0.0015)\\F = 800 [N]](https://tex.z-dn.net/?f=%280.15%2A8%29-%28F%2A0.0015%29%20%3D%20%280.15%2A0%29%5C%5CF%2A0.0015%20%3D%200.15%2A8%5C%5CF%20%3D%201.2%2F%280.0015%29%5C%5CF%20%3D%20800%20%5BN%5D)
Note: The force is taken as negative since it is exerted by the nail on the hammer and this force is directed in the opposite direction to the movement of the hammer.
Answer:
Explanation:
mass of refrigerator, m = 110 kg
coefficient of static friction, μs = 0.85
coefficient of kinetic friction, μk = 0.59
(a) the minimum force required to just start the motion in refrigerator
F = μs x mg
F = 0.85 x 110 x 9.8
F = 916.3 N
(b) The force required to move the refrigerator with constant speed
F' = μk x mg
F' = 0.59 x 110 x 9.8
F' = 636.02 N
(c) Let a be the acceleration.
Net force = Applied force - friction force
F net = 950 - 636.02
F net = 313.98 N
a = F net / mass
a = 313.98 / 110
a = 2.85 m/s²