Qualification > Sciences
Edexcel PHYSICS Doubts
astarmathsandphysics:
1)Because lost energy is used to overcome the friction force, and the kinetic energy is converted into heat via friction
2)Some of the energy input to raise the water is lost to friction, and some of the potential energy of the water is also lost to friction as it falls.
I like jokes, so you have to live with them.
dk bose:
1)At Acapulco,divers jump from a cliff 36m high into the sea.At the base of the cliff there is a ledge which sticks out a distance of 6.4m.What must be the diver's minimum horizontal velocity in order to miss this ledge and enter the sea safely?
2)An aeroplane carrying out a parcel releases a parcel while travelling at a steady speed of 90m/s at an altitude of 200m.calculate:
a)th time between the parcel leaving the aeroplane and it striking the ground.
b)the horizontal distance travelled by the parcel in this time .
c)the speed at which the parcel strikes the ground.
astarmathsandphysics:
here you are dk
dk bose:
1)A hockey player passes the ball at 15m/s to a team mate who stops it completely in 0.1s.What force does the receiver's stick have to apply to the ball?
2)A penalty stroke is flicked from a distance of 6.40m from the goal line.The striker scoops it so that the ball leaves the ground at 45 degrees angle and a speed of 8m/s.How does the goalkeeper have to make a save before the ball crosses the goal line?
3)The study of mechanics in sport is a popular and often profitable new idea of scientific study. Descibe how a sport scientist could use ICT to collect data to study the movement of players and equipment overtime. Explain why technological developments have made the data collected more valid and reliable than with traditional methods of studying mechanics.
astarmathsandphysics:
1)f*t=m*v Need to know the mass
2)I presume you mean to find the height
The horizontal speed is 8cos 45=5.656m/s
Use x=u_x t to find the time:t=x/u_x =6.4/5.656=1.132 s
now work vertically
s=?
u=8sin45=5.656
v=? (not needed)
a=-9.8
t=1.132 s
s=ut+1/2at^2 =5.656*1.132-1/2*-9.8*1.132^2=0.12m the ball crosses at a height of 0.12m
3)Fit all the players with trackers and take their position every second. Computers are more reilable and can gather and analyse data methodically.
3)
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