Answer:
D thermal energy moves from the marshmallow to your fingers as you touch the marshmallow
Explanation:
Conduction is the movement of thermal energy without the actual movement of the particles of a body. They particles only collide with each other and transfer energy in the process while maintaining their mean positions.
Answer:
-2.8 m/s²
Explanation:
Acceleration: This can be defined as the rate of change of velocity The S. I unit of acceleration is m/s²
Using the equation of motion,
v² = u² + 2as................... Equation 1
Where v = Final velocity, u = initial velocity, a = acceleration, s = distance,
Given: v = 6.0 m/s, u = 8.0 m/s, s = 5.0 m.
Substituting into equation 1
6² = 8²+2(a)5
36 = 64 + 10a
10a = 36-64
10a = -28
10a/10 = -28/10
a = -2.8 m/s²
Note: a is negative because because the skater decelerate on the rough ice
Hence the magnitude of her acceleration is = -2.8 m/s²
Answer:
6.2N force
Explanation:
According to Newton's second law of motion, force is equal to the product of the mass of a body and its acceleration. Mathematically,
Force = mass × acceleration
Given mass of bucket of water = 6.2kg
acceleration of the bucket = 1m/s²
Force exerted on the rope = 6.2 × 1
= 6.2N
The elastic potential energy of a spring is given by

where k is the spring's constant and x is the displacement with respect to the relaxed position of the spring.
The work done by the spring is the negative of the potential energy difference between the final and initial condition of the spring:

In our problem, initially the spring is uncompressed, so

. Therefore, the work done by the spring when it is compressed until

is

And this value is actually negative, because the box is responsible for the spring's compression, so the work is done by the box.