Answer:
Kinetic energy cannot be negative
potential energy is a reference dependent quantity and it can be positive as well as negative both
Since potential energy is defined only for conservative force so it can not be found for friction force
Explanation:
Kinetic energy of an object is given by the formula
here we know that
m = mass of object that can not be negative
v = speed of the object and since its square is given here so it can not be negative
so Kinetic energy is always positive
potential energy is given as the energy due to the virtue of the position of object
so it is
so potential energy is a reference dependent quantity and it can be positive as well as negative both
Since potential energy is defined only for conservative force so it can not be found for friction force
Answer: 450J
Explanation:
Mass of ball = 1.0kg
kinetic energy = ?
velocity of the ball = 30m/s
Kinetic energy is the energy possessed by a moving object. It is measured in joules, and depends on the mass (m) of the object and the velocity (v) by which it moves
i.e K.E = 1/2mv²
KE = 1/2 x 1.0kg x (30m/s)^2
KE = 0.5 x 1.0 x 900
KE = 450J
(Recall that kinetic energy is equal to potential energy at the top of its ascent)
So, if KE = 450J; PE = 450J
Thus, the potential energy of the ball is 450 joules.
Answer:
The impala pushed down the ground with a force of 37.49N
Explanation:
The force at which the impala pushed down the ground can be calculated for using the Newton's second law of motion,
Force = mass × acceleration
Force = mass ×(velocity/time)
Given mass = 25.5kg
Time = 0.21seconds
To get the velocity, we will use one of the equation of motions;
Using v² = u²+2gH
where;
H is the height reached from the ground = 2.5m
g = 9.81m/s²
u is the initial velocity = 0m/s
v is the final velocity=?
Substituting this values to get the final velocity v;
v² = 0²+2(9.81)(2.5)
v² = 49.05
v = √49.05
v = 7.0m/s
Substituting this velocity into the formula for force we have;
Force = 25.5×(7.0/0.21)
Force = 25.5 × 1.47
Force = 37.49N
The impala pushed down the ground with a force of 37.49N
Answer: A) In case of dark energy increasing significantly, the universe would accelerate its expansion at an ever-increasing rate which later on may result in "Big Rip".
B) In case of dark energy decreasing significantly, the universe would decelerate its expansion which later on may result in "Big Crunch".
Explanation:
In case of significant increase in dark energy, the universe would accelerate its expansion at more increasing rate. Ultimately the expansion would result in scale factor becoming infinite within a finite period of time. As a result due to the repulsive dominance of dark energy the whole universe would come apart resulting in a situation called "Big Rip"
If dark energy were to decrease significantly enough with time, the accelerating expansion of the universe that is observed now would start to decelerate as the mass once again dominates over dark energy. It will result in universe reversing its expansion resulting in its collapse, a situation called "Big Crunch".
Hope it helps!!!
Answer:
total kinetic energy is 8 × J
Explanation:
given data
potential difference = 5 V
e = 1.60 × C
to find out
what is kinetic energy
solution
we will apply here conservation of energy that is
change in potential energy is equal to change in kinetic energy
so
change potential energy is e × potential difference
change potential energy = 1.60 × × 5
change potential energy = 8 × J
so change in kinetic energy = 8 × J
and we know proton start from rest that mean ( kinetic energy is 0 ) so
change in KE is total KE
total kinetic energy is 8 × J