It's 120N downwards. net force is adding or subtracting the x and y values
The minimum initial velocity that the ball must have for it to reach the top of the hill is 21 m/s. The correct option is D.
<h3>What is mechanical energy?</h3>
The mechanical energy is the sum of kinetic energy and the potential energy of an object at any instant of time.
M.E = KE +PE
A boy is trying to roll a bowling ball up a hill. The friction is ignored. The ball must have to reach the top of the hill with a velocity. The acceleration due to gravity, g = 9.8 m/s²
The conservation of energy principle states that total mechanical energy remains conserved in all situations where there is no external force acting on the system.
M.E bottom of hill = M.E on top of hill
Kinetic energy + Potential energy = Kinetic energy + Potential energy
1/2 mu² + 0 = 0 + mgh
At the top of hill, the velocity will become zero. So, final kinetic energy is zero.
Substituting the values, we have
1/2 x u² = 9.8 x 22.5
u = sqrt [2 x9.8 x 22.5 ]
u= 21 m/s
Thus, the minimum initial velocity that the ball must have for it to reach the top of the hill is 21 m/s.
Learn more about mechanical energy.
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Place the object in an electronic balance and measure its mass.
Place a measured amount of water in the cylinder.
Place the object in the cylinder so that it’s fully submerged.
Measure the new level of the liquid and subtract the original level. This is equal to the volume of the object.
Density = mass / volume.
Answer:
5 miles
Explanation:
the bus is going 60km/hour meaning its going a mile a minute and it went on for 5 minutes meaning it went for 5 minutes/
Given: Radius of the Moon Rm = 1.74 x 10⁶ m
Mass of the Moon Mm = 7.35 X 10²² Kg
Universal Gravitational constant G = 6.67 X 10⁻¹¹ N.m²/Kg²
Required: acceleration due to gravity g = ?
Formula: g = GMm/Re²
g = (6.67 x 10⁻¹¹ N.m²/Kg²)(7.35 x 10²² Kg/(1.74 x 10⁶ m)²
g = 4.90 x 10¹² N.m²/Kg/3.0 x 10¹² m²
g = 1.63 m/s²
