Answer:
Tools that require electricty like drills
Explanation:
Answer:
(d) Negative.
Explanation:
let's test each at a time.
(a) It can't be 0, because cup would slide back other wise.
(b) Positive, well if forward is positive, than the work done against the forward acceleration must be negative , so it can't be positive.
(c) Equal to non-conservative work done by the car's engine.
well no, because work done by car's engine dosen't go all of it into getting car to move, so it can't be that.
(d) negative, this look like it, because work that friction does must be nagative to counteract positive thrust of car which is positive and in forward direction.
(d) this can't be true.
So the answer is (d) negative.
A nitrogen laser generates a pulse containing 10.0 mj of energy at a wavelength of 340.0 nm and has 1785 x 10¹⁹ photons in the pulse.
<h3>How many photons are in the pulse?</h3>
Energy of a single photon is
E=hcλ
E=6.626×10⁻³⁴ J s×3×108 m/s /340×10⁻⁹ m
E=6.31×10⁻¹⁹ J
Number of photons in the laser is
n=Total Energy/Energy per photon
n=10⁷×10⁻³J /5.90×10⁻¹⁹J/photon
n= 1785 x 10¹⁹ photons
To learn about photons, refer: brainly.com/question/20912241?referrer=searchResults
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1. A wheelchair ramp. Instead of using lifting force on the wheelchair, You use push or pull force on it.
2. A slide. Instead of throwing down an item, It uses gravitational potential energy make an object "move" down the slide.
3.A screw. It's reducing the force by twisting the screw out of something instead of pulling it out. (Sorry about my bad grammar).
