In what type of change is matter not destroyed
2 answers:
You might be interested in
The cart travelled a distance of 14.4 m
Explanation:
The work done by a force when pushing an object is given by:
where:
F is the magnitude of the force
d is the displacement
is the angle between the direction of the force and the displacement
In this problem we have:
W = 157 J is the work done on the cart
F = 10.9 N is the magnitude of the force
, assuming the force is applied parallel to the motion of the cart
Therefore we can solve for d to find the distance travelled by the cart:
Learn more about work:
#LearnwithBrainly
Answer:
θ = 13.7º
Explanation:
- According to the work-energy theorem, the change in the kinetic energy of the combined mass of the child and the sled, is equal to the total work done on the object by external forces.
- The external forces capable to do work on the combination of child +sled, are the friction force (opposing to the displacement), and the component of the weight parallel to the slide.
- As this last work is just equal to the change in the gravitational potential energy (with opposite sign) , we can write the following equation:
- ΔK, is the change in kinetic energy, as follows:
- ΔU, is the change in the gravitational potential energy.
- If we choose as our zero reference level, the bottom of the slope, the change in gravitational potential energy will be as follows:
- Finally, the work done for non-conservative forces, is the work done by the friction force, along the slope, as follows:
- Replacing (2), (3), and (4) in (1), simplifying common terms, and rearranging, we have:
- Replacing by the givens and the knowns, we can solve for sin θ, as follows:
⇒ θ = sin⁻¹ (0.236) = 13.7º