Obviously D. 7.5
Why?
Well, 7.5 is exactly between 7 and 8.
a. How much work did you do? Hint: The force is the weight of the snow.
b. What was your power in watts? Hint: You must always convert time to seconds when calculating power.
Gravitational potential energy increases; kinetic energy increases.
B.
Kinetic energy equals gravitational potential energy.
C.
Kinetic energy increases; gravitational potential energy decreases.
D.
The mass of the ball is required to answer this.
The ball originally contains potential energy and no kinetic energy, therefore we can use the theory of conservation of mechanical energy. Its total energy, which is made up of the KE and PE, is constant and equal to its starting PE as it falls. Thus, option C is correct.
As the ball falls toward the ground, its gravitational potential energy is transformed into kinetic energy. The kinetic energy of the ball will increase as it accelerates until it collides with something. The ball's collision generates kinetic energy, which is transformed into several forms of energy.
As it rises, the ball's speed slows until the very apex of its motion, where it briefly pauses. At the peak, it accelerates at -9.8 m/s2.
Therefore, A ball is thrown up into the air, yet although though it rises into the air, the direction, and velocity of the ball are actually downward.
Learn more about kinetic energy here:
#SPJ2
B. a boulder falling off a cliff in a straight path
C. a ball being thrown straight up
D. a bicyclist moving in a straight line at a constant speed
Accelerated motion refers to any motion with changing velocity, including changes in speed or direction. Most of the examples provided involve accelerated motion, except for the bicyclist moving in a straight line at a constant speed, as both speed and direction remain constant in such scenario.
In the context of physics, accelerated motion refers to any motion in which the velocity changes - either in magnitude (speed) or direction. This can be due to an increase or decrease in speed, or a change in direction. Examples of accelerated motion include an airplane taking off down a straight runway, a boulder falling off a cliff in a straight path, and a ball being thrown straight up.
However, a bicyclist moving in a straight line at a constant speed is NOT an example of accelerated motion. In this case, the speed (magnitude of velocity) and direction are both constant, and therefore there is no acceleration present.
#SPJ6
Speed of light in the medium = 2.14×10⁸ ms⁻1.
The refraction of a medium = 1.4
We know that speed of light in air= 3×10⁸ m/s
The ratio of the speed of the light in air to the speed of the light in medium is defined as refractive index.
Refractive index = speed of light in air ÷ speed of light in medium
1.4 = 3×10⁸ ÷ speed of light in medium
speed of light in medium = 3×10⁸ ÷ 1.4
= 214285714.2857 km/s
Hence, the speed of light in that medium is = 214285714.2857 km/s
Learn more about the refractive index
#SPJ5