Answer:
Explanation:
The equation for Power is
P = Work/time to do work and the equation for work is
Work = FΔx
We first need to find the amount of work done, then we can find the power it took to do that work.
W = 2000(9.8)(28) so
W = 550,000 N*m
Now we fill that into the power equation:
gives us
P = 18000 Watts. But we need kW, so we divide by 1000 to get
P = 18 kW of power.
The acceleration of gravity on or near the surface of the Earth is 9.8 m/s².
Anything acted on only by gravity loses 9.8 m/s of upward speed, or gains
9.8 m/s of downward speed, every second.
Leaping straight upward at 1.8 m/s, Tina keeps rising until she runs out of
upward speed. That happens in (1.8/9.8) = 0.1837 second after the leap.
After that, Finkel's First Law of Motion takes over:
"What goes up must come down."
The dropping part of the leap is symmetrical with the first. Please don't
make me go through proving it. Tina hits the floor at the same speed of
1.8 m/s with which she left it, and it takes the same amount of time to drop
from the peak to the floor as it took to rise from the floor to the peak.
So her total time out of contact with the floor is
2 x (0.1837 sec) = 0.367 second (rounded)
The meat in the freezer is frozen.
Everything else in the freezer is frozen too.
Nothing in the refrigerator is frozen.
The freezer is colder than the refrigerator. <span>
Mildred takes a pound of frozen hamburger meat out of the freezer
and puts it into the refrigerator. The meat is colder than anything
else that's in there.
Heat flows from the air in the refrigerator into the frozen hamburger (C)
and warms up the meat. When the temperature of the meat warms up
to the temperature of the air in the refrigerator, the heat stops flowing.</span>
Answer:
Explanation:
Acceleration is the change in velocity with respect to time.
Acceleration = change in velocity/Time
Acceleration = final velocity - initial velocity/Time
Given initial velocity = 10m/s
Final velocity = 20m/s
Time taken = 4s
Acceleration = 20-10/4
Acceleration = 10/4
Acceleration =2.5m/s²
For the second part of the question:
Given parameters
initial velocity = 15m/s
acceleration = -3m/s²
time = 4seconds
a = v-u/t
-3 = v-15/4
cross multiply
-12 = v-15
add 15 from both sides
-12+15 = v-15+15
3 = v
<em>Hence the final velocity of the car is 3m/s</em>
Answer:
v = 5.75 x 10⁶ m/s
Explanation:
The radius (r) of the circular orbit taken by a charged particle is related to its speed perpendicular to a magnetic field of strength B, and is given by
r = 
--------------(i)
Where,
q = charge of the particle
m = mass of the particle
Making v subject of the formula in equation (i) above gives
v = 
-------------------(ii)
Given;
r = 20cm = 0.2m
B = 0.3T
v = unknown
q = charge of proton = 1.6 x 10⁻¹⁹ C
m = mass of the proton = 1.67 x 10⁻²⁷kg
Substitute the values of m, q, B and r into equation (ii) above to get;
v = 
Solving for v gives:
v = 5.75 x 10⁶ m/s
Therefore, the velocity of the proton is 5.75 x 10⁶ m/s
