Answer:
Ben's average speed was twice Debby's average speed.
Explanation:
Ben covered a total distance of 16 miles (10+4+2) and Debby covered 8 miles (3+2+2+1) which is half of what Ben covered. As they both reached the place in the same amount of time it tells us Ben was faster.
Answer:
wrong statement : Momentum is not conserved for a system of objects in a head-on collision.
Explanation:
In a head on collision of two objects , two equal and opposite forces are created at the point of collision . These two forces create two impulses in opposite direction which results in equal and opposite changes in momentum in each of them . Hence net change in momentum is zero. In this way momentum is conserved in head on collision of two objects.
Answer:
it needs to be shaken but make sure you have enough room to shake it safely
Explanation:
To properly operate the laboratory thermometer it needs to be shaken but make sure you have enough room to shake it safely. This done because there is a small bend in the mercury channel of a clinical thermometer that uses mercury. You must shake the thermometer to get the mercury from a previous reading from the thermometer back into the bulb for taking new reading. The bend prevents flow back into the tube so that one can comfortably take reading.
Answer:
<h2>468,750 J</h2>
Explanation:
The kinetic energy of an object can be found by using the formula
m is the mass
v is the velocity
From the question we have
We have the final answer as
<h3>468,750 J</h3>
Hope this helps you
Answer:
i)-6.25m/s
ii)18 metres
iii)26.5 m/s or 95.4 km/hr
Explanation:
Firstly convert 90km/hr to m/s
90 × 1000/3600 = 25m/s
(i) Apply v^2 = u^2 + 2As...where v(0m/s) is the final speed and u(25m/s) is initial speed and also s is the distance moved through(50 metres)
0 = (25)^2 + 2A(50)
0 = 625 + 100A....then moved the other value to one
-625 = 100A
Hence A = -6.25m/s^2(where the negative just tells us that its deceleration)
(ii) Firstly convert 54km/hr to m/s
In which this is 54 × 1000/3600 = 15m/s
then apply the same formula as that in (i)
0 = (15)^2 + 2(-6.25)s
-225 = -12.5s
Hence the stopping distance = 18metres
(iii) Apply the same formula and always remember that the deceleration values is the same throughout this question
0 = u^2 + 2(-6.25)(56)
u^2 = 700
Hence the speed that the car was travelling at is the,square root of 700 = 26.5m/s
In km/hr....26.5 × 3600/1000 = 95.4 km/hr
