Answer: 22.6 hours
Explanation:
The power is the measure of the rate of energy.
In this problem, the 12.0 V battery is rated at 51.0 Ah, which means it delivers 51.0 A of current in a time of t = 1 h = 3600 s. The power delivered by the battery can be written as

where
I is the current
V = 12.0 V is the voltage of the battery
So the energy delivered by the battery can be written as

Where

So the energy delivered is

At the same time, the headlight consumes 27.0 W of power, so 27 Joules of energy per second; Therefore, it will remain on for a time of:

Answer:
Good question to ask in physics, sir maam
For vertical motion, use the following kinematics equation:
H(t) = X + Vt + 0.5At²
H(t) is the height of the ball at any point in time t for t ≥ 0s
X is the initial height
V is the initial vertical velocity
A is the constant vertical acceleration
Given values:
X = 1.4m
V = 0m/s (starting from free fall)
A = -9.81m/s² (downward acceleration due to gravity near the earth's surface)
Plug in these values to get H(t):
H(t) = 1.4 + 0t - 4.905t²
H(t) = 1.4 - 4.905t²
We want to calculate when the ball hits the ground, i.e. find a time t when H(t) = 0m, so let us substitute H(t) = 0 into the equation and solve for t:
1.4 - 4.905t² = 0
4.905t² = 1.4
t² = 0.2854
t = ±0.5342s
Reject t = -0.5342s because this doesn't make sense within the context of the problem (we only let t ≥ 0s for the ball's motion H(t))
t = 0.53s
Answer:
31677.2 lb
Explanation:
mass of hammer (m) = 3.7 lb
initial velocity (u) = 5.8 ft/s
final velocity (v) = 0
time (t) = 0.00068 s
acceleration due to gravity (g) 32 ft/s^{2}
force = m x ( a + g )
where
- m is the mass = 3.7 lb
- g is the acceleration due to gravity = 32 ft/s^{2}
- a is the acceleration of the hammer
from v = u + at
a = (v-u)/ t
a = (0-5.8)/0.00068 = -8529.4 ( the negative sign showa the its decelerating)
we can substitute all required values into force= m x (a+g)
force = 3.7 x (8529.4 + 32) = 31677.2 lb