Average velocity = (displacement) / (total time)
Displacement = distance and direction between
the starting point and the end point
The car travels 90 meters north, then 40 meters south.
So it ends up 50 meters north of where it began.
Displacement = 50 meters north
Total time = (15 + 5) = 20 seconds
Average velocity = (50 meters north) / (20 seconds)
= 2.5 m/s north
Strength/magnitude would both work
#1
As we know that energy of electromagnetic wave is given by
so here we know that penetrating power will directly depends on its energy and energy inversely depends on wavelength
So here we can say correct answer will be
C) The penetrating power decreases as the wavelength increases.
#2
Speed of sound is maximum in solids and minimum in gas
so here as ice melts into water the speed of sound must have to decrease
so correct answer will be
D) The speed of sound would decrease because sound travels faster through solids than liquids.
#3
mechanical waves required medium to travel while non mechanical waves do not require any medium to travel
so here correct answer will be
A) sound
Answer:
It cannot be constant because if it does not change and each time it increases its strength and speed.
Explanation:
Answer:
a. 5 × 10¹⁹ protons b. 2.05 × 10⁷ °C
Explanation:
Here is the complete question
A beam of protons is moving toward a target in a particle accelerator. This beam constitutes a current whose value is 0.42 A. (a) How many protons strike the target in 19 seconds? (b) Each proton has a kinetic energy of 6.0 x 10-12 J. Suppose the target is a 17-gram block of metal whose specific heat capacity is 860 J/(kg Co), and all the kinetic energy of the protons goes into heating it up. What is the change in temperature of the block at the end of 19 s?
Solution
a.
i = Q/t = ne/t
n = it/e where i = current = 0.42 A, n = number of protons, e = proton charge = 1.602 × 10⁻¹⁹ C and t = time = 19 s
So n = 0.42 A × 19 s/1.602 × 10⁻¹⁹ C
= 4.98 × 10¹⁹ protons
≅ 5 × 10¹⁹ protons
b
The total kinetic energy of the protons = heat change of target
total kinetic energy of the protons = n × kinetic energy per proton
= 5 × 10¹⁹ protons × 6.0 × 10⁻¹² J per proton
= 30 × 10⁷ J
heat change of target = Q = mcΔT ⇒ ΔT = Q/mc where m = mass of block = 17 g = 0.017 kg and c = specific heat capacity = 860 J/(kg °C)
ΔT = Q/mc = 30 × 10⁷ J/0.017 kg × 860 J/(kg °C)
= 30 × 10⁷/14.62
= 2.05 × 10⁷ °C
