Jaroslav puts some items into his rucksack. The table shows the weight of each item.
Item
Weight
2 apples
120g each
2 bottles
water
524g each
474g
camera
86g
map
mobile phone
214g
umbrella
339g
The rucksack has a weight of 275g.
Work out the total weight of the rucksack and all the items.
Give your answer in kilograms.​

Aspacecraft can attain a stable orbit 300 kilometers above earth if it reaches a velocity of 7.7 kilometers per second. the formula for a rocket's maximum velocity v in kilometers per second is vequalsminus0.0098tplusc ln upper r, where t is the firing time in seconds, c is the velocity of the exhaust in kilometers per second, and r is the ratio of the mass of the rocket filled with fuel to the mass of the rocket without fuel. find the velocity of a spacecraft whose booster rocket has a mass ratio of 20, an exhaust velocity of 2.1 km/s, and a firing time of 15 s. can the spacecraft achieve a stable orbit 300 km above earth?