Answer:
The hiker has to climb 941.26 to ''work off'' the calories.
Explanation:
Let's first find out how much energy the hiker gets from 150 food calories.
This is:
Energy = 150 * 4186
Energy = 627.9 kJ
To burn all of this off, we set it equal to the gravitational potential energy, and then solve for the height.
This is:
Gravitational Potential Energy (G.P.E) = 629700
G.P.E = mass * gravity * height
Thus,
mass * gravity * height = 629700
68 * 9.81 * height = 629700
height = 941.26 meters
Answer:
Kinetic Energy
Explanation:
The potential energy is being converted into kinetic energy. The hitter has struck the ball transferring the kinetic energy from the swinging bat to the ball.
The answer is: [D]: "force".
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Note the formula: " F = ma" ; {"Force = mass * acceleration"}.
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The force needed to the stop the car is -3.79 N.
Explanation:
The force required to stop the car should have equal magnitude as the force required to move the car but in opposite direction. This is in accordance with the Newton's third law of motion. Since, in the present problem, we know the kinetic energy and velocity of the moving car, we can determine the mass of the car from these two parameters.
So, here v = 30 m/s and k.E. = 3.6 × 10⁵ J, then mass will be

Now, we know that the work done by the brake to stop the car will be equal to the product of force to stop the car with the distance travelled by the car on applying the brake.Here it is said that the car travels 95 m after the brake has been applied. So with the help of work energy theorem,
Work done = Final kinetic energy - Initial kinetic energy
Work done = Force × Displacement
So, Force × Displacement = Final kinetic energy - Initial Kinetic energy.

Thus, the force needed to the stop the car is -3.79 N.
#28
Fluid always flow from higher pressure to lower pressure so as we can see the figure liquid is coming out of the spray bottle so it clearly shows that the pressure outside the tube will be lower than the pressure inside the tube.
#29
Momentum is defined as product of mass and its velocity
so here we will have

here we have


so we will have

