Answer:
A (2066,6 N)
Explanation:
Use the Work formula
62.000J = F . 30
62.000/30 = 2066,6 N
The amout of time it took to move the rock doesn´t matter at all.
It is called a distraction variable, We don´t need it to solve the problem it is there just to confuse.
Answer:
Power = 20 Watts
Explanation:
Given the following data;
Voltage = 100 V
Resistance = 500 Ohms
To find the power that is required to light a lightbulb;
Mathematically, power can be calculated using the formula;

Substituting into the formula, we have;


Power = 20 Watts
A) 0.189 N
The weight of the person on the asteroid is equal to the gravitational force exerted by the asteroid on the person, at a location on the surface of the asteroid:

where
G is the gravitational constant
8.7×10^13 kg is the mass of the asteroid
m = 130 kg is the mass of the man
R = 2.0 km = 2000 m is the radius of the asteroid
Substituting into the equation, we find

B) 2.41 m/s
In order to orbit just above the surface of the asteroid (r=R), the centripetal force that keeps the astronaut in orbit must be equal to the gravitational force acting on the astronaut:

where
v is the speed of the astronaut
Solving the formula for v, we find the minimum speed at which the astronaut should launch himself and then orbit the asteroid just above the surface:

Mass (m)=55kg
acceleration (a)=9.81 m/s^2, this is the acceleration due to gravity.
initial velocity=0m/s. The skydiver doesn’t start with any speed because she is on the plane or helicopter.
final velocity=16m/s This is the velocity (speed) the skydiver reaches
The equation we use is KE=.5mv^2
Kinetic energy=.5 mass x velocity^2
KE=.5(55kg)(16m/s)^2
KE=.5(55kg)(256m/s)
KE=.5(14080J)
J=Joules
KE=7040J
Kinetic energy is 7040 Joules (J)
Hope this helps
Answer:
50 meters
Explanation:
Let's start by converting to m/s. There are 3600 seconds in an hour and 1000 meters in a kilometer, meaning that 72km/h is 20m/s.

Since the car starts at rest, you can write the following equation:

Now that you have the acceleration, you can do this:

Once again, there is no initial velocity:

Hope this helps!