Explanation:
First, find the velocity of the projectile needed to reach a height h when fired straight up.
Given:
Δy = h
v = 0
a = -g
Find: v₀
v² = v₀² + 2aΔy
(0)² = v₀² + 2(-g)(h)
v₀ = √(2gh)
Now find the height reached if the projectile is launched at a 45° angle.
Given:
v₀ = √(2gh) sin 45° = √(2gh) / √2 = √(gh)
v = 0
a = -g
Find: Δy
v² = v₀² + 2aΔy
(0)² = √(gh)² + 2(-g)Δy
2gΔy = gh
Δy = h/2
The minimum force required to lift the box at constant velocity is determined as 274.4 N.
<h3>
Minimum force required</h3>
The minimum force required to lift the box at constant velocity is the tension in one of the pulleys, and the magnitude is calculated as follows;
2T = mg
where;
- m is mass of the box
- T is the minimum force required
2T = mg
T = mg/2
T = (56 x 9.8)/2
T = 274.4 N
Learn more about minimum force here: https://brainly.in/question/47873510
#SPJ1
1. U = Q + W
U = -500 + 1000
U = 500 J
2. The first law of thermodynamic is about the law of conservation of energy where energy in should be equal to energy out.
3. It is the windmill that does not transform energy from heat to mechanical instead it is the transforms the opposite.
4. In a heat engine, work is used to transfer thermal energy from a hot reservoir to a cold one.
5. 5.00 × 10^4 J - 2.00 × 10^4 J = 3.00 × 10^4 J
6. To increase the work done, we raise the temperature of the cold reservoir.
The amount of energy used in the billing period is 5,400,000,000 joules.
One kWH is the amount of energy transferred in one hour, there 1 kWh is equal to
1 kWh=1*1000*(J/s)*3600 s
=3600000 J
Thus the amount of energy in joules consumed by the user for the billing period is =1500*3600000=5,400,000,000 J.
The amount of energy used in the billing period is 5,400,000,000 joules.
Answer:
Explanation:
The sig figs are off in the answer (unless you use -9.81 for the acceleration due to gravity. My classes always use -9.8, which is 2 sig figs. But nevertheless, we can solve it!) Use the velocity formula:
where vf is the final velocity, v0 is the initial velocity, a is the acceleration due to gravity, and t is the time in seconds. Filling in, using the fact that both the velocities are negative since the ball is going down:
-24.5 = -12.1 +(-9.8)t or
-24.5 = -12.1 - 9.8t and
-12.4 = -9.8t and divide to get that
t = 1.27 sec
